Pulsatile turbulent pipe flow

The unsteady turbulent flow generated in a pipe by a pulsating pressure gradient is studied. Saffman's turbulence model is employed. In this model turbulence is characterized by two quantities, namely the pseudo-energy e and pseudo-vorticity omega. Previous results on the wall pseudo-vorticity function are extended in order to apply the model to unsteady conditions. The reliability of the results is tested by performing a comparison between predictions and experimental data. It is shown that at least in the present unsteady flow production, dissipation, convection and diffusion of turbulence are all important components of the energy budget, even in wall layers. The failure of the logarithmic velocity distribution follows.